Bearing assemblies may be used between moving parts to provide free movement between the parts and/or to limit movement between the parts. Because bearing assemblies are often used in dynamic environments, performance and the life of a bearing assembly may depend on changes in the dynamic environment, for example, the temperature, pressure, and contamination. In some cases, bearing assemblies may include one or more sealing elements, which may be used to prevent entry of contaminants, to maintain certain pressure conditions, and/or to grip or manipulate sealed components using friction.
For example, a bearing and seal assembly used in some drilling applications, referred to as a rotating control head or rotating control device (“RCD”), includes a bearing and seal assembly that enables rotation of a drill string and longitudinal motion of a drill string as the wellbore is drilled, while maintaining a fluid-tight seal between the drill string and the wellbore so that drilling fluid discharged from the wellbore may be discharged in a controlled manner. By controlling discharge of the fluid from the wellbore, a selected fluid pressure may be maintained in the annular space between the drill string and an exterior of the wellbore.